Process of making molded polyurethane articles

ABSTRACT

The invention provides polyurethane components and compositions capable of providing internal mold release properties in SRIM applications. The polyol composition of the invention has an isocyanate reactive polyol (A) having a number average molecular weight from 100 to about 10,000 and an effective amount of internal mold release composition (B) having a silicon-containing polymer (a) and an at least diester functional compound (b) which is the reaction product of (i) an aromatic carboxylic acid, and (ii) alcohols having from 2 to 30 carbons. The invention further provides an SRIM polyurethane composition useful in the preparation of molded polyurethane articles having internal mold release properties, the composition comprising an isocyanate component (I) and the isocyanate reactive polyol composition (component (II)) disclosed above. In another aspect of the invention, the invention provides methods of using the claimed compositions as well as the rigid cellular polyurethane SRIM articles resulting from such processes.

1. BACKGROUND OF THE INVENTION

The present invention relates to molded, cellular, polyurethane articleshaving internal mold release capabilities, compositions for use in thepreparation of such articles, and methods of making such articles. Moreparticularly, the invention relates to rigid, cellular moldedpolyurethane articles produced by structural reaction injection molding(SRIM) processes. The molded articles of the invention may becharacterized as having densities ranging from 15 to 40 pcf. Mostparticularly, the invention relates to rigid, cellular polyurethane SRIMarticles having fiberglass reinforcement therein, the articles havinginternal mold release capabilities.

Molded cellular and noncellular polyurethane articles have found manyapplications in the automotive and building industries. Illustrativeautomotive applications include the use of such articles as consoles,door panels, pillars and seat backs. Examples of non-automotive usesinclude modular housing and shower supports and doors. Although manypolyurethane molded parts are produced by reaction injection moldingprocesses (RIM), it has been found that the use of woven or non-wovenfiber reinforcements can provide parts with greater tensile strength andflex modulus. Such molding processes are known as structural reactioninjection molding (SRIM).

SRIM processes may be generally described as the pouring or injecting ofa liquid foam composition into a closed or open mold which, if open, issubsequently closed during the foaming reaction. Prior to the pouring inof the liquid foam composition, reinforcing fiberglass mats and/or othersuitable plastic reinforcing parts are placed in the open mold. In somecases, a cosmetic facing or cover stock material will initially be laidin the open mold prior to the placement of the reinforcing materialsand/or liquid foaming composition. When such cover stock materials areused, and the liquid foam composition is subsequently poured into thepartially filled mold, the process is known as a back filling orpour-behind SRIM process.

Although SRIM molders are faced with problems unique to their particularprocesses, they are also faced with the problems attendant to anytraditional polyurethane molding process. In any molding operation,efficiency and cost considerations mandate that the length of timerequired to make each part be minimized as much as possible. As aresult, it is highly desirable that each part be removed from the moldas rapidly and as easily as possible.

However, those skilled in the art will appreciate that moldedpolyurethane parts often resist release from the mold. Traditionally,external mold release (EMR) agents have been applied onto the moldsurface each time a new part is to be molded. The use of such EMR agentsis highly disadvantageous for two reasons. First, the use of the EMRagents adds significantly to the per part cost. Factors such as the costof the EMR agent per application, the cost of the labor or equipmentrequired to apply the EMR agent, and the cost of the time during whichthe mold is open but is nonfunctioning, must all be included whenevaluating the additional cost per part resulting from the use of EMRagents. Second, the EMR agents often include volatile components whichresult in a need for air cleaning and/or ventilation equipment. Fans,blowers, and protective gear all represent a significant capitalinvestment. As a result, polyurethane molders have long desired internalmold release (IMR) agents which are mixed with one or more of thepolyurethane components and are thus present during each molding cycle.Such internal mold release agents are intended to appear at theinterface between the mold wall cavity and the reacting ingredients toeffect sufficient non-adherence between the two so that release andremoval of the molded article can be easily accomplished.

Examples of previous prior art attempts to provide IMR agents aredisclosed in several U.S. patents. Illustrative is U.S. Pat. No.4,111,861, which discloses compositions and methods for formingpolyether polyurethanes utilizing internal mold release additivesselected from four disclosed classes, i.e., (1) mixtures of aliphatic oraryl carboxylic acid and a polar metal compound, (2)carboxyalkylsiloxanes, (3) aliphatic glyoximes, and (4) aralkylquaternary ammonium salts.

U.S. Pat. No. 3,875,069 discloses lubricant compositions useful in theshaping of thermoplastic materials comprising a mixture of (A) mixedesters of aliphatic polyols, dicarboxylic acids and long chainedaliphatic monocarboxylic acids, and (B) esters of the groups: (1) estersof dicarboxylic acids and long chained aliphatic monofunctionalalcohols, (2) esters of long chained aliphatic monocarboxylic acids, (3)complete or partial esters of aliphatic polyols and long chainedaliphatic monocarboxylic acids, in a ratio of (A) to (B) of from 1:3 to9:1.

U.S. Pat. Nos. 4,052,495 and 4,457,887, assigned to Dow CorningCorporation, respectively disclose siloxane-polyoxyalkylene copolymersand silicones intended for use as internal mold release agents in themolding of polyurethanes articles.

Similarly, U.S. Pat. Nos. 4,498,929, 4,546,145, 4,504,314, and4,477,366, assigned to ICI, disclose internal mold release agentsincorporating particular polysiloxane compounds.

However, very few prior art attempts at providing internal mold releaseagents have been successfully directed towards SRIM applications. Theprocess of molding SRIM articles provides unique challenges to thesuccessful incorporation of IMR agents. The use of the IMR agents mustnot interfere with or detract from the internal adhesion of thepolyurethane composition to internal components like the fiberglass matand/or polymer based structural reinforcing elements. Likewise, the IMRagent on the exterior surface of the finished SRIM article must notinterfere with adhesion between the article and external components likecover stocks used in a pour-behind SRIM applications. Finally, the useof the IMR agents must not interfere with the flow characteristics orreactivity profile of the polyurethane composition. Those skilled in theart will appreciate that the polyurethane compositions used in SRIMapplications must exhibit superior flowability and generally lowviscosity in order to accommodate the presence of the reinforcingmaterials.

In addition to the performance requirements of the finished SRIMarticle, those skilled in the art will appreciate that it would behighly desirable to achieve polyol compositions capable of providinginternal mold release properties which exhibit minimal separationbehavior upon standing. Those skilled in the art will appreciate thatIMR agents often exhibit separation behavior when combined in either thepolyol component or the isocyanate component of a polyurethanecomposition. Such separation behavior represents special processingchallenges and often requires the use of costly processing and/or mixingequipment.

It is thus an object of the invention to provide an internal moldrelease agent which is capable of use in SRIM compositions andapplications and which reduces the need to apply EMR agents.

It is a further object of the invention to provide a polyol compositionhaving an internal mold release agent therein which exhibits minimalseparation behavior and which, when used in SRIM applications, providesrigid, cellular polyurethane articles exhibiting good adhesion to bothinternal and external components. It is a further object of the instantinvention to provide a foam composition for the preparation of moldedpolyurethane articles having internal mold release properties, whereinthe polyol component of the composition exhibits little or no separationbehavior and the composition results in rigid, cellular polyurethanearticles exhibiting good adhesion to both internal and externalcomponent elements.

Finally, it is an object of the invention to provide improved methods ofmaking SRIM articles, wherein the articles have internal mold releaseproperties and the need to apply EMR agents is reduced.

2. SUMMARY OF THE INVENTION

These objects and more are satisfied with the compositions of theinvention. The internal mold release composition and the polyolcomposition of the invention are capable of providing internal moldrelease properties to an SRIM polyurethane system and reducing the needfor EMR agents.

The internal mold release composition of the invention includes asilicon-containing polymer (a) and an at least diester functionalcompound (b) which is the reaction product of (i) an aromaticdicarboxylic acid, and (ii) alcohols having from 2 to 30 carbons.

The polyol composition of the invention requires an isocyanate reactivepolyol (A) having a molecular weight from 100 to about 10,000 and aneffective amount of an internal mold release composition (B) having asilicon containing polymer (a) and an at least diester functionalcompound (b) which is the reaction product of (i) an aromaticdicarboxylic acid, and (ii) alcohols having from 2 to 30 carbons.

The invention further provides a composition useful in the preparationof molded polyurethane articles having internal mold release properties,the composition comprising an isocyanate component (I), and anisocyanate reactive polyol component (II) requiring an isocyanatereactive polyol (A) having a molecular weight from 100 to about 10,000and an effective amount of an internal mold release composition (B)requiring a silicon containing polymer (a) and an at least diesterfunctional compound (b) which is the reaction product of (i) an aromaticdicarboxylic acid, and (ii) alcohols having from 2 to 30 carbons.

It has been found that use of the polyol component and polyurethanecomposition as disclosed herein provides several advantages. Significantimprovements in productivity and a decrease in overall cycle time havebeen realized. More particularly, demold times of SRIM articles havebeen realized which are less than one minute and in some cases less than50 seconds. In addition, it has been found that little or greatlyreduced amounts of external mold release agent are required. Finally,molds appear to be easier to clean when the compositions of theinvention are used.

The invention also provides methods of utilizing the disclosed polyoland polyurethane compositions as well as the articles produced by suchmethods.

In particular, the invention provides a process of making a moldedpolyurethane article having internal mold release properties, the methodrequiring the providing of a mold; placing in the mold, a compositioncomprising an isocyanate component (I) and an isocyanate reactive polyolcomponent (II), component (II) requiring an isocyanate reactive polyol(A) having a molecular weight from 100 to about 10,000, as well as aneffective amount of an internal mold release composition (B),composition (B) having an silicon-containing polymer (a) and an at leastdiester functional compound (b) which is the reaction product of (i) anaromatic dicarboxylic acid, and (ii) alcohols having from 2 to 30carbons; and allowing the composition to react within the mold for atime sufficient to produce a molded polyurethane article having internalmold release properties.

Finally, the invention provides a method a making a composite moldedarticle, the method requiring placing a cover stock within a compositearticle mold; subsequently placing within the composite article mold amolded polyurethane SRIM article having internal mold releaseproperties, the SRIM article being produced by a process requiringproviding an SRIM article mold, placing in the SRIM article mold, anSRIM composition having an isocyanate component (I), and an isocyanatereactive polyol component (II), component (II) having an isocyanatereactive polyol (A) and an effective amount of an internal mold releasecomposition (B), composition (B) having an silicon-containing polymer(a) and an at least diester functional compound (b) which is thereaction product of (i) an aromatic dicarboxylic acid, and (ii) alcoholshaving from 2 to 30 carbons, allowing the composition to react withinthe SRIM article mold for a time sufficient to produce a moldedpolyurethane SRIM article having internal mold release properties, andremoving the article from the SRIM article mold; providing within thecomposite article mold, a polyurethane foam composition; and allowingthe polyurethane foam composition to react within the composite articlemold for a time sufficient to produce a composite molded article.

3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The polyurethane composition of the invention requires an isocyanatecomponent (I) and an isocyanate reactive polyol component (II).Isocyanate reactive polyol component (II) must, at a minimum, have anisocyanate reactive polyol (A) having a molecular weight from 100 toabout 10,000 and an effective amount of internal mold releasecomposition (B).

Internal mold release composition (B) requires a silicon-containingpolymer (a) and an at least diester functional compound (b) which is thereaction product of (i) an aromatic dicarboxylic acid, and (ii) alcoholshaving from 2 to 30 carbons. It has been found that the combination ofcomponents (a) and (b) exhibits synergism and provides unexpectedadvantageous internal mold release properties to SRIM articles andmolding processes. The particular combination of (a) and (b), in thedisclosed proportions, provides advantageous release results as comparedto the performance of (a) or (b) alone.

The silicon-containing polymer (a) will generally be a silicone, i.e. apolymer containing the moiety --Si(R₂)O--. The silicon-containingpolymer (a) preferably utilized in the invention contains two or moresecondary hydroxyl groups, and preferably an average of three hydroxylgroups per silicon-containing polymer molecule. In a particularlypreferred aspect of the invention, the silicon-containing polymer is adimethylsiloxane compound which is represented by the following genericformula: ##STR1## wherein each of R are independently an alkyl radicalhaving 1 to 20 carbon atoms; an alicyclic, an aryl, an alkaryl or anaralkyl having 1 to 25 carbon atoms in the alkyl group; an aliphaticether group; or a polyester group; and wherein a secondary hydroxylfunctional group is substituted onto at least two, preferably onto eachof the R groups;

each of A are independently one or more silicon atoms containing alkyl,alicyclic, cycloalkyl, aryl, alkyloxy, alkaryl, aralkyl, or arylalkoxyhave a 1 to 25 carbon atoms in each aliphatic portion; anorganosiloxane; hydrogen; or an alkyl having 1 to 25 carbon atoms;

n is an integer from 1 to 10; and

the sum of w+x+y+z totals an integer which would correspond to anaverage hydroxyl equivalent weight ranging from 200 to 4,000.

Preferably, each of R are independently an alkyl having from 1 to 10carbon atoms, an alkoxy, or an ether having the formula: ##STR2## andpreferably A is hydrogen, a C₁ -C₄ alkyl, or a siloxane having theformula: ##STR3## wherein n is an integer from 1 to 6, and w+x+y+ztotals an integer corresponding to an average hydroxyl equivalent weightof the molecule ranging from 1,250 to 3,000.

In the most preferred embodiment of the invention, thesilicon-containing polymer (a) used in the invention will be DowCorning®¹ 1248 fluid, sold by Air Products of Allentown, Pa. or anycommercially available equivalent. A commercially available equivalentis believed to be DABCO®² DC5000. The 1248 fluid has an average of 3hydroxyl sites per molecule and an average hydroxyl equivalent weight ofabout 1,725 to 2,225, and most likely about 2,000. It is believed thatthis fluid corresponds with the formula: ##STR4## wherein each n isindependently an integer ranging from 1 to 4, and w+x+y+z is about 70,or corresponds to average hydroxyl equivalent weight of a molecule ofabout 2,000. The methods of manufacture of such silicon-containingpolymers is generally described in U.S. Pat. No. 4,130,708, thedisclosure of which is hereby incorporated by reference.

The second component of the internal mold release composition of theinvention is an at least diester functional compound (b) which is areaction product of (i) an aromatic dicarboxylic acid and (ii) alcoholshaving from 2 to 30 carbons.

The aromatic dicarboxylic acids (i) will generally have from between 8to 14 carbon atoms. The aromatic dicarboxylic acids may be mononuclearor polynuclear. Examples of suitable mononuclear aromatic dicarboxylicacids are phthalic acid, terephthalic acid and isophthalic acid.Examples of suitable polynuclear aromatic dicarboxylic acids includenaphthalic acid and diphenyl-o,o'-dicarboxylic acid. Mononucleararomatic dicarboxylic acids are preferred. Especially preferred isphthalic acid.

The second reactant used in making the at least diester functionalcompound (b) is an alcohol (ii) having from 2 to 30 carbons. A widevariety of alcohols are suitable for use in producing compound (b).Preferred alcohols are aliphatic monofunctional alcohols. The alcoholsmay be linear, branched or even to highly branched oxo alcohols. Linearalcohols are most suitable. Aliphatic monofunctional alcohols havingfrom 2 to 30 carbons are preferred. More preferred are aliphaticmonofunctional alcohols having from 4 to 15 carbons. Most preferably,the aliphatic monofunctional alcohols (i) will have from 8 to 11carbons. Examples of suitable monofunctional aliphatic alcohols includeambutyl alcohol, isobutyl alcohol, isohexyl alcohol, 1,3'-dimethylbutylalcohol, heptyl alcohol, octyl alcohol, 2-ethylhexyl alcohol, isooctylalcohol, oxo alcohol, dodecyl alcohol, undecyl alcohol, tridecylalcohol, isotridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol,isohexyldecyl alcohol, styro alcohol, and behenyl alcohol, alcohols of12 to 30 carbons such as oleyl alcohol, as well as alcohol mixtures thatare obtained by hydrogenating fatty acid mixtures of 12 to 30 carbonatoms obtained from natural fats and oils, such as olive oil, grapeseedoil, coconut oil, palm oil, soybean oil, cottonseed oil, and linseedoil.

The alcohols (i) used to react with the aromatic dicarboxylic acid (i)may be a single suitable alcohol or may be a mixture of 2 or moresuitable alcohols. It will be appreciated that the use of a singlesuitable alcohol will result in the formation of diesters (b) having astructure (R'OOCRCOOR") wherein R is an aromatic structure and R' and R"are identical. The use of two or more suitable alcohols will result incompounds (b) having a structure (R'OOCRCOOR") wherein R is an aromaticstructure and R' and R" are nonidentical. While it is possible to usemixtures of various monofunctional alcohols, it is most preferred that asingle alcohol be used such that diesters of identical structure, i.e.R'OOCRCOOR', are formed. However, it is within the scope of theinvention to use esters (b) wherein R' and R" are different.

Particularly preferred reactants for use in making the at least diesterfunctional compound (b) are phthalic acid and undecyl alcohol.Accordingly, a particularly preferred at least diester functionalcompound (b) is di-undecyl phthalate or DUP.

The reactants (i) and (ii) will generally be reacted in a manner knownto those skilled in the art. That is, the production of the at leastdiester functional compounds (b) are effected according to knownesterification methods, for example, esterifying the hydroxyl groups ofthe alcohols (ii) with the aromatic dicarboxylic acids (i) to producecomplete esterification. In general, one mole of the dicarboxylic acid(i) will be reacted with two moles of the monofunctional alcohols, (ii).

As indicated above, it has unexpectedly been found that the combinationof (a) and (b) provides unexpectedly advantageous internal mold releaseproperties. As a result, at a minimum, the internal mold releasecomposition (B) will have from 1 to 99 parts by weight of thesilicon-containing polymer (a) and from 99 to 1 parts by weight of thecompound (b), all parts by weight being based on the total weight of theinternal mold release composition (B).

More particularly, it has been found that good internal mold releaseproperties are obtained when the IMR composition (B) contains from 1 to50 parts by weight of the silicon-containing polymer (a), and from 50 to99 parts by weight of the at least diester functional compound (b).

Optimum internal mold release properties have been achieved where theinternal mold release composition (B) contains from 1 to 15 parts byweight of the silicon-containing polymer (a) and from 85 to 99 parts byweight of compound (b).

In general, the polyol composition (II) of the invention (also known asthe resin side or polyol component) should contain from about 10 to 60weight percent of the internal mold release composition (B) based on thetotal weight of the polyol composition. That is, out of 100 pounds of apolyol composition, comprised of a mixture of isocyanate-reactive polyol(A) and internal mold release composition (B), from 10 to 60 poundsshould be IMR composition (B) while from 90 to 40 pounds isisocyanate-reactive polyol (A). Those skilled in the art will appreciatethat increasing amounts of the internal mold release composition (B)will provide the best release properties while increasing amounts of theisocyanate reactive polyol (A) will generally provide the best overallperformance properties in the finished molded polyurethane SRIMarticles.

It has been found that ideally, the internal mold release composition(B) will be present in a weight ratio of approximately 1 parts IMR agent(B) to 2 parts polyol (A). That is, in a total of 99 parts by weight ofthe polyol composition of the invention (i.e. polyol component (II)), 33parts by weight will be internal mold release composition (B), while 66pounds are comprised of isocyanate reactive polyol (A).

Examples of suitable isocyanate reactive polyols (A) are compoundshaving at least two isocyanate reactive hydrogens which are intended tobe employed in the preparation of polyurethane foams and elastomers.Such compounds are often prepared by the catalytic condensation of analkylene oxide or mixture of alkylene oxides either simultaneously orsequentially with an organic compound having at least two activehydrogen atoms, such as evidenced by U.S. Pat. Nos. 1,922,459;3,190,927; and 3,346,557. Representative polyols includepolyhydroxyl-containing polyesters and polycarbonates, polyoxyalkylenepolyether polyols such as the aforementioned polyoxyalkylene polyetherpolyols, polyhydroxy-terminated polyurethane polymers,polyhydroxyl-containing phosphorous compounds, and alkylene oxideadducts of polyhydric polythioesters, polyacetals, aliphatic polyols andthiols, ammonia, and amines including aromatic, aliphatic, andheterocyclic amines, as well as mixtures thereof. Alkylene oxide adductsof compounds which contain two or more different groups within theabove-defined classes may also be used, for example, amino alcoholswhich contain an amino group and a hydroxyl group. Also, alkylene oxideadducts of compounds which contain one SH group and one OH group as wellas those which contain an amino groups and an SH group may be used.Generally, the number average molecular weight of the polyols will varyfrom greater than 400 to 10,000. It has been found, however, thatnitrogen containing molecules, particularly those with amino groups, arepreferred initiators.

Suitable hydroxy-terminated polyester may be used such as thoseprepared, for example, from polycarboxylic acids and polyhydricalcohols. Any suitable polycarboxylic acid may be used such as oxalicacid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelicacid, suberic acid, azelaic acid, sebacic acid, brassylic acid, thapsicacid, maleic acid, fumaric acid, glutaconic acid, a-hydromuconic acid,β-hydromuconic acid, a-butyl-a-ethyl-glutaric acid, a,β-diethylsuccinicacid, isophthalic acid, terephthalic acid, hemimellitic acid, and1,4-cyclohexanedicarboxylic acid. Any suitable polyhydric alcohol,including both aliphatic and aromatic, may be used such as ethyleneglycol, propylene glycol, trimethylene glycol, 1,2-butanediol,1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,4-pentanediol,1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, glycerol,1,1,1-trimethylolpropane, 1,1,1-trimethylolethane, 1,2,6-hexanetriol,a-methyl glucoside, pentaerythritol, and sorbitol. Also included withinthe term "polyhydric alcohols" are compounds derived from phenol such as2,2-bis(4-hydroxylphenyl)propane, commonly known as Bisphenol A.

The hydroxyl-containing polyester may also be a polyester amide such asis obtained by including some amine or amino alcohol in the reactantsfor the preparation of the polyesters. Thus, polyester amides may beobtained by condensing an amino alcohol such as ethanolamine with thepolycarboxylic acids set forth above or they may be made using the samecomponents that make up the hydroxyl-containing polyester with only aportion of the components being a diamine such as ethylene diamine.

Any suitable polyoxyalkylene polyether polyol may be used such as thepolymerization product of an alkylene oxide or a mixture of alkyleneoxides with a polyhydric alcohol. Any suitable polyhydric alcohol may beused such as those disclosed above for use in the preparation of thehydroxy-terminated polyesters. Suitable initiators include bothaliphatics and aromatics, such as ethylene glycol, propylene glycol,dipropylene glycol, trimethylene glycol, 1,2-butanediol, 1,3-butanediol,1,4-butanediol, 1,2-pentanediol, 1,4-pentanediol, 1,5-pentanediol,1,6-hexanediol, 1,7-heptanediol, glycerol, 1,1,1-trimethylolpropane,1,1,1-trimethylolethane, 1,2,6-hexanetriol, a-methyl glucoside,pentaerythritol, and sorbitol. Any suitable alkylene oxide may be usedsuch as those disclosed above for preparing the prepolymers. Examples ofalkylene oxides include ethylene oxide, propylene oxide, butylene oxide,amylene oxide, mixtures thereof, tetrahydrofuran, alkyleneoxide-tetrahydrofuran mixtures, epihalohydrins, and aralkylene oxidessuch as styrene oxide. Polyethers which are particularly suitableinclude the alkylene oxide addition products of trimethylolpropane,glycerin, propylene glycol, dipropylene glycol; sucrose and blendsthereof having number average molecular weights of from 100 to 5,000.

Suitable polyhydric polythioethers which may be condensed with alkyleneoxides include the condensation product of thiodiglycol or the reactionproduct of a dicarboxylic acid such as is disclosed above for thepreparation of the hydroxyl-containing polyesters with any othersuitable thioether glycol.

Polyhydroxyl-containing phosphorous compounds which may be used includethose compounds disclosed in U.S. Pat. No. 3,639,542. Preferredpolyhydroxyl-containing phosphorous compounds are prepared from alkyleneoxides and acids of phosphorous having an acid equivalency of from about72 percent to about 95 percent.

Suitable polyacetals which may be condensed with alkylene oxides includethe reaction product of formaldehyde or other suitable aldehyde with adihydric alcohol or an alkylene oxide such as those disclosed above.

Suitable aliphatic thiols which may be condensed with alkylene oxidesinclude alkanethiols containing at least two --SH groups such as1,2-ethanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, and1,6-hexanedithiol; alkene thiols such as 2-butene-1,4-dithiol; andalkyne thiols such as 3-hexyne-1,6-dithiol.

As indicated above, polyols having initiator molecules containingnitrogen are particularly suitable for use in the invention.Particularly preferred for use in the invention are the polyethersresulting from the condensation of amines with alkylene oxides. Suitableamines which may be condensed with alkylene oxides include aromaticamines such as aniline, o-chloroaniline, p-aminoaniline,1,5-diaminonaphthalene, methylene dianiline, the condensation productsof aniline and formaldehyde, and 2,3-, 2,6-, 3,4-, 2,5-, and2,4-diaminotoluene (TDA) and mixtures of the isomers; and aliphaticamines such as methylamine, triisopropanolamine, ethylenediamine,1,3-diaminopropane, 1,3-diaminobutane, and 1,4-diaminobutane. Polyethershaving aromatic amines as initiator molecules are most preferred.

Polyols containing ester groups can also be employed in the subjectinvention. These polyols are prepared by the reaction of an alkyleneoxide with an organic dicarboxylic acid anhydride and a compoundcontaining reactive hydrogen atoms. A more comprehensive discussion ofthese polyols and their method of preparation can be found in U.S. Pat.Nos. 3,585,185; 3,639,541 and 3,639,542.

Polyols containing graft polymer dispersions may also be employed in theinvention. These are prepared by the in situ polymerization, in thepolyols listed below, of an ethylenically unsaturated monomer or amixture of ethylenically unsaturated monomers. Representativeethylenically unsaturated monomers which may be employed in the presentinvention include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene,1,7-octadiene, styrene, a-methylstyrene, 2-methylstyrene,3-methylstyrene and 4-methylstyrene, 2,4-dimethylstyrene, ethylstyrene,isopropylstyrene, butylstyrene, phenylstyrene, cyclohexylstyrene,benzylstyrene, and the like; substitute styrenes such as cyanostyrene,nitrostyrene, N,N-dimethylaminostyrene, acetoxystyrene, methyl4-vinylbenzoate, phenoxystyrene, p-vinylphenyl oxide, and the like; theacrylic and substituted acrylic monomers such as acrylonitrile, acrylicacid, methacrylic acid, methyl acrylate, 2-hydroxyethyl acrylate, methylmethacrylate, cyclohexyl methacrylate, benzyl methacrylate, isopropylmethacrylate, octyl methacrylate, methacrylonitrile, ethyla-ethoxyacrylate, methyl a-acetaminoacrylate, butyl acrylate,2-ethylhexyl acrylate, phenyl acrylate, phenyl methacrylate,N,N-dimethylacrylamide, N,N-dibenzylacrylamide, N-butylacrylamide,methacrylyl formamide, and the like; the vinyl esters, vinyl ethers,vinyl ketones, etc., such as vinyl acetate, vinyl butyrate, isopropenylacetate, vinyl formate, vinyl acrylate, vinyl methacrylate, vinylmethoxyacetate, vinyl benzoate, vinyltoluene, vinylnaphthalene, vinylmethyl ether, vinyl ethyl ether, vinyl propyl ethers, vinyl butylethers, vinyl 2-ethylhexyl ether, vinyl phenyl ether, vinyl 2methoxyethyl ether, methoxybutadiene, vinyl 2-butoxyethyl ether,3,4-dihydro-1,2-pyran, 2-butoxy-2'-vinyloxy diethyl ether, vinyl methylketone, vinyl ethyl ketone, vinyl phosphonates such as vinyl phenylketone, vinyl ethyl sulfone, N-methyl-N-vinyl acetamide,N-vinyl-pyrrolidone, vinyl imidazole, divinyl sulfoxide, divinylsulfone, sodium vinylsulfonate, methyl vinylsulfonate, N-vinyl pyrrole,and the like; dimethyl fumarate, dimethyl maleate, maleic acid, crotonicacid, fumaric acid, itaconic acid, monomethyl itaconate,t-butylaminoethyl methacrylate, dimehtylaminoethyl methacrylate,glycidyl acrylate, allyl alcohol, glycol monoesters of itaconic acid,vinyl pyridine, and the like. Any of the known polymerizable monomerscan be used and the compounds listed above are illustrative and notrestrictive of the monomers suitable for use in this invention.Preferably, the monomer is selected from the group consisting ofacrylonitrile, styrene and mixtures thereof.

The amount of ethylenically unsaturated monomer employed in thepolymerization reaction is generally from 25 percent to 70 percent,preferably from 30 percent to 45 percent, based on the total weight ofthe product. The polymerization occurs at a temperature between about25° C. and 180° C., preferably from 80° C. to 135° C.

The unsaturated polyols or macromers which may be employed in preparinga graft polymer dispersion, if used, may be prepared by the reaction ofany conventional polyol such as those described above with an organiccompound having both ethylenic unsaturation and a hydroxyl, carboxyl,anhydride, isocyanate or epoxy group or they may be prepared byemploying an organic compound having both ethylenic unsaturation and ahydroxyl, carboxyl, anhydride, or epoxy group as a reactant in thepreparation of the conventional polyol. Representative of such organiccompounds include unsaturated mono- and polycarboxylic acids andanhydrides such as maleic acid and anhydride, fumaric acid, crotonicacid and anhydride, propenyl succinic anhydride, acrylic acid, acryloylchloride, hydroxy ethyl acrylate or methacrylate and halogenated maleicacids and anhydrides, unsaturated polyhydric alcohols such as2-butene-1,4-diol, glycerol allyl ether, trimethylolpropane allyl ether,pentaerythritol allyl ether, pentaerythritol vinyl ether,pentaerythritol diallyl ether, pentaerythritol vinyl ether,pentaerythritol diallyl ether, and 1-butene-3,4-diol, unsaturatedepoxides such as 1-vinyl-cyclohexene-3,4-epoxide, butadiene monoxide,vinyl glycidyl ether(1-vinyloxy-2,3-epoxy propane), glycidylmethacrylate and 3-allyloxypropylene oxide (allyl glycidyl ether).

Illustrative polymerization initiators which may be employed are thewell-known free radical types of vinyl polymerization initiators such asthe peroxides, persulfates, perborates, percarbonates, azo compounds,etc. These include hydrogen peroxide, dibenzoyl peroxide, acetylperoxide, benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butylperoxide, lauroyl peroxide, butyryl peroxide, diisopropylbenzenehydroperoxide, cuanene hydroperoxide, paramenthane hydroperoxide,diacetyl peroxide, di-a-cumyl peroxide, dipropyl peroxide, diisopropylperoxide, isopropyl-t-butyl peroxide, butyl-t-butyl peroxide, difuroylperoxide, bis(triphenylmethyl) peroxide, bis(p-methoxybenzoyl) peroxide,p-monomethoxybenzoyl peroxide, rubene peroxide, ascaridol, t-butylperoxybenzoate, diethyl peroxyterephthalate, propyl hydroperoxide,isopropyl hydroperoxide, n-butyl hydroperoxide, t-butyl hydroperoxide,cyclohexyl hydroperoxide, trans-decalin hydroperoxide, a-methylbenzylhydroperoxide, a-methyl-a-ethyl benzyl hydroperoxide, tetralinhydroperoxide, triphenylmethyl hydroperoxide, diphenylmethylhydroperoxide, a,a'-azobis-(2-methyl heptonitrile), 1,1'-azo-bis(cyclohexane carbonitrile), 4,4'-azobis(4-cyanopentanoic acid),2,2'-azobis(isobutyronitrile), 1-t-butylazo-1-cyanocyclohexane,persuccinic acid, diisopropyl peroxy dicarbonate,2,2'-azobis(2,4-dimethylvaleronitrile),2-t-butylazo-2-cyano-4-methoxy-4-methylpentane,2,2'-azobis-2-methylbutanenitrile,2-t-butylazo-2-cyanobutane, 1-t-amylazo-1-cyanocyclohexane,2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile,2,2'-azobis-2-methylbutyronitrile, 2-t-butylazo-2-cyano-4-methylpentane,2-t-butylazo-2-isocutyronitrile, to butylperoxyisopropyl carbonate andthe like; a mixture of initiators may also be used. The preferredinitiators are 2,2'-azobis(2-methylbutyronitrile),2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile),2-t-butylazo-2-cyano-4-methoxy-4-methylpentane,2-t-butylazo-2-cyano-4-methylpentane, 2-t-butylazo-2-cyano-butane andlauroyl peroxide. Generally, from about 0.1 percent to about 10 percent,preferably from about 1 percent to about 4 percent, by weight ofinitiator based on the weight of the monomer will be employed in theprocess of the invention.

However, while many of the above described polyols are suitable for usein the invention, it has been found that certain polyols areparticularly preferred. It has been unexpectedly discovered thatproblems of nonhomogeneity, or separation behavior, are largelyeliminated when the isocyanate reactive polyol comprises at least onepolyoxyalkylene polyether which has as an initiator molecule, an aminesubstituted aromatic molecule. Preferred examples are aniline,o-chloroaniline, p-aminoaniline, 1,5-diaminonaphthalene, methylenedianiline, the condensation products of aniline and formaldehyde, and2,3-, 2,6-, 3,4-, 2,5-, and 2,4-diaminotoluene (TDA). The most preferredtype of aromatic polyamine initiator is diaminotoluene having vicinalamino groups, i.e., 2,3- or 2,6- diaminotoluene and mixtures thereof.

In addition, the most preferred polyoxyalkylene polyethers for use inthe instant invention will be those which have been oxypropylated.

Thus, the preferred polyol for use in the instant invention will be anoxypropylated TDA polyether. The most preferred such polyols willgenerally have a relatively low molecular weight, i.e. below 1,000 and ahydroxyl number of generally less than 600. An example of a mostpreferred commercially available polyol is PLURACOL® Polyol 736 fromBASF Corporation of Wyandotte, Mich.³

While not wishing to be bound to a particular mechanism, it is believedthat the structure of the oxypropylated aromatic polyamine polyether isresponsible for the observed lack of separation in the novel polyolcomposition of the invention.

The polyol side or composition (II) of the invention may further containadditional components such blowing agents, catalysts, chain extendingagents, surface active agents, adhesion promoters, stabilizers, dyes,fillers, pigments and/or mixtures thereof.

For example, a particularly preferred blowing agent is water, preferably0.5 to 10 percent by weight, and more particularly, 1 to 5 weightpercent of water based on the weight of the polyol (A). Alternatively,instead of water alone, mixtures of water and chemically inert, lowboiling hydrocarbons or halogenated hydrocarbons can also be used asfoaming agents. Suitable hydrocarbons and halogenated hydrocarbons willbe those having boiling points below 50° C., preferably between 50° C.and 30° C. at atmospheric pressure. Illustrative examples arehalogenated hydrocarbons such as monochlorodifloromethane,dichloromonofloromethane, dichlorofloromethane, andtrichlorofloromethane and are mixtures, as well has hydrocarbons such asisomers of propane, butane, pentane as well as dimethylether.

The required quantities of blowing agent mixture can be determinedexperimentally in a very simple matter as a function of the mixing ratioof water to hydrocarbon blowing agents as well as the desired densitiesof the foam. Suitable amounts generally range from approximately 2 to40, preferably 5 to 25 percent blowing agent based on the weight of thepolyol.

Chain extending agents and/or crosslinking agents will also preferablybe employed in the preparation of the molded polyurethane articles.Examples of suitable chain extenders and/or crosslinking include thosecompounds having at least two functional groups bearing active hydrogenatoms such as water, hydrazine, primary and secondary diamines, aminoalcohols, amino acids, hydroxy acids, glycols, or mixtures thereof. Suchagents will generally have a number average molecular weight of lessthan about 400. A preferred group of chain extending agents and/orcrosslinking agents include water, ethylene glycol, 1,4-butanediol,glycerin and mixtures thereof. The most preferred crosslinking agent isglycerin.

The use of catalysts is highly preferred. Examples of suitableamine-based catalysts which may be used include tertiary amines such as,for example, triethylenediamine, N-methylmorpholine, N-ethylmorpholine,diethylethanolamine, N-cocomorpholine,1-methyl-4-dimethylaminoethylpiperazine, 3-methoxypropyldimethylamine,N,N,N'-trimethylisopropyl propylenediamine,3-diethylaminopropyldiethylamine, dimethylbenzylamine, and the like.Other suitable catalysts are the metal-based catalysts, for example,stannous chloride, dibutyltin di-2-ethyl hexanoate, stannous oxide, aswell as other organometallic compounds such as are disclosed in U.S.Pat. No. 2,846,408. Preferred catalysts however, are those commerciallyavailable amine catalysts such as DABCO® TMR-3, DABCO® BL-17, DABCO®X-8154, and DABCO® 33LV, all of which are commercially available fromAir Products Corporation. A particularly suitable metal-based catalystis dioctyltin dimercaptin commercially available as FOMREZ® UL-32catalyst. The most preferred catalyst will be a mixture of amine- andmetal-based catalysts.

Surfactants will also preferably be incorporated with the invention. Aparticularly preferred surfactant is L-550, a cell stabilizingsurfactant, commercially available from Union Carbide. It is believedthat the presence of this surfactant provides improved flowcharacteristics.

As indicated above, the IMR composition (B) will most preferably be partof the polyol component (II) of a polyurethane system. However, it iswithin the scope of the invention to have IMR composition (B)incorporated in the isocyanate component (I) of a polyurethane system.Alternatively, components (a) and (b) of IMR composition (B) couldrespectively be separately incorporated into polyol component (II) andisocyanate component. (I) In either case, the concentrations of (a) and(b) would be as given above.

The isocyanate reactive polyol component (II) of the invention isgenerally combined with an isocyanate component (I) to provide thepolyurethane compositions of the invention. The polyurethanecompositions of the invention are suitable for the preparation of moldedSRIM polyurethane articles having internal mold release properties.Isocyanate components (I) suitable for use in accordance with theinvention are organic isocyanates. The organic polyisocyanates employedin the instant invention correspond to the formula R'(NCO) z wherein R'is a polyvalent organic radical which is either aliphatic, arylalkyl,alkylaryl, aromatic or mixtures thereof and z is an integer whichcorresponds to the valence of R' and is at least 2. Representative ofthe types of organic polyisocyanates contemplated herein include, forexample, 1,2-diisocyanatoethane, 1,3-diisocyanatopropane,1,2-diisocyanatopropane, 1,4-diisocyanatobutane,1,5-diisocyanatopentane, 1,6-dissocyanatohexane,bis(3-isocyanatopropyl)ether, bis(3-isocyanatopropyl)sulfide,1,7-diisocyanatoheptane, 1,5-diisocyanato-2,2-dimethylpentane,1,6-diisocyanate-3-methoxyhexane, 1,8-diisocyanatoctane,1,5-diisocyanato-2,2,4-trimethylpentane, 1,9-diisocyanatononame,1,10-diisocyanatopropyl ether of 1,4-butylene glycol,1,11-diisocyanatoundecane, 1,12-diisocyanatododecane,bis(isocyanatohexyl)sulfide, ,4-diisocyanatobenze,1,3-diisocyanato-o-xylene, 1,3-diisocyanato-p-xylene,1,3-diisocyanato-m-xylene, 2,4-diisocyanto-1-chlorobenzene,2,4-diisocyanato-1-nitro-benzene, 2,5-diisocyanato-1-nitrobenzene,m-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluenediisocyanate, mixtures of 2,4- and 2,6-toluene diisocyanate,16-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate,1,4-cyclohexane diisocyanate, hexahydrotoluene diisocyanate,1,5-naphthalene diisocyanate, 1-methoxy-2,4-phenylene diisocyanate,4,4'-cyclohexane diisocyanate, hexahydrotoluene diisocyanate,1,5-naphthalene diisocyanate, 1-methoxy-2,4-phenylene diisocyanate,4,4'-diphenylmethane diisocyanate, 4,4'-biphenylene diisocyanate,3,3'-dimethyl-4,4'-diphenylmethane diisocyanate,3,3'-dimethyl-4,4'-diphenylmethane diisocyanate and3,3'-dimethyldiphenylmethane-4,4'-diisocyanate and3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; the triisocyanates suchas 4,4',4"-triphenylmethane triisocyanate polymethylene polyphenylenepolyisocyanate and 2,4,6-toluene triisocyanate; and the tetraisocyanatessuch as 4,4'-dimethyl-2,2'-5,5'-diphenylmethane tetraisocyanate.Especially useful due to their availability and properties are toluenediisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethanediisocyanate, polymethylene polyphenylene polyisocyanate, and mixturesthereof.

The polyisocyanates are prepared by conventional methods known in theart such as the phosgenation of the corresponding organic amine.Included within the useable isocyanates are the modifications of theabove isocyanates which contain carbodiimide, allophonate orisocyanurate structures. Quasi-prepolymers may also be employed in theprocess of the subject invention. These quasi-prepolymers are preparedby reacting an excess of organic polyisocyanate or mixtures thereof witha minor amount of an active hydrogen-containing compound as determinedby the well-known Zerewitinoff test as described by Kohler in Journal ofthe American Chemical Society, 49, 3181 (1927). These compounds andtheir methods of preparation are well known in the art. The use of anyone specific active hydrogen compound is not critical hereto, rather anysuch compound can be employed herein. Generally, the quasi-prepolymershave a free isocyanate content of from 20 percent to 40 percent byweight.

The isocyanate component (I) and the polyol component (II) willgenerally be combined in an index of from 60 to 120, and preferably anindex of from 80 to 110. The most preferred index for the polyurethanecomposition will be from 85 to 95.

The polyurethane composition of the invention maybe used with variousreinforcement materials to produce SRIM articles in both conventionalSRIM processes and pour behind processes.

As indicated above, conventional SRIM processes generally require thepouring of a liquid polyurethane composition into an open or closedmold, which, if open, is subsequently closed during the foamingreaction. Prior to the pouring in of the liquid foam composition,reinforcing materials and/or reinforcing parts are placed in the openmold. Reinforcement materials suitable for use in producing SRIMarticles include a wide variety of materials. Fiber reinforcements arepreferred. Fiber materials may be woven, non-woven (random), orcombinations thereof. Suitable fibers include synthetic fibers of nylon,polyester, aramide, polyether ketones, polyether sulfones, polyamides,silicon carbon, and the like; natural fibers such as cellulose, cotton,hemp, flaxes, and jute; and mineral or ceramic fibers includingWollastonite, aluminum, glass fibers, and carbon fibers. A uniquenon-glass material is Colback®⁴ spun bonded non-woven comprised of abiocomponent fiber having a polyester core and polyamide skin availablefrom AKZO Corporation, Enka, N.C. Glass fiber, either woven ornon-woven, is the preferred reinforcement material due to its low costand physical properties.

One or more layers of fiber reinforcement may be used depending on thedesired fiber weight. Up to 70 weight percent of the SRIM part maycomprise reinforcement material. In general, the reinforcing materialwill laid directly into the mold and the liquid polyurethane foamcomposition poured thereon. However, alternatively or in additionthereto, chopped fibers and other fillers may be added to the isocyanatecomponent of the system, the polyol component, or both, in amounts up toabout 70 weight percent of the SRIM part.

However, SRIM processes wherein fiberglass mats are placed in the moldprior to the injection of the polyurethane composition are preferred.

In addition to the fiber reinforcing material, structural parts orelements comprised of wood, metal and/or plastic type materials known tothose skilled in the art, may be laid in the mold either prior to orsubsequent to the placing of the fiber reinforcement in the open mold.Metal and plastic elements are preferred. Examples of suitable plasticmaterials include ABS, nylon, acetyl, polypropylene, polyethylene, PVCand the like. In either case, the liquid polyurethane foam compositionwill generally be applied last, prior to the closing of the mold or theinitiation of molding.

In traditional SRIM processes, after the molding of the SRIM article,the article will be trimmed. However, in some uses the molded SRIMarticle will be used as a component for a composite article. Forexample, a cover stock material may be laid into a open mold, followedby the molded SRIM article. A flexible or semi-flexible polyurethanefoam is then injected into the mold containing the cover stock materialand the molded SRIM article. The flexible or semi-flexible foam isallowed to react to bind the cover stock and the molded SRIM articleinto a single composite article.

Alternatively, composite articles can be made using back-filling orpour-behind processing techniques. For example, in a typical pour-behindprocess a cover stock material is laid into a foam. Such cover stocksmay or may not have expanded foam backing. Optionally, a second foamsuch as an energy absorbing foam may be placed in the top of the mold.Alternatively, reinforcing materials may be placed in the mold. Theliquid polyurethane composition is subsequently poured onto the coverstock and molding initiated. In an open mold, molding will be initiatedby closing the mold. The foam is allowed to react for a period of timesufficient for it to completely react and adhere to the cover stockmaterial and any other component elements previously placed in the mold.

Examples of suitable cover stock materials are vinyl, polyvinylchloride, polypropylene, polyethylene, cloth, polyurethane foams,including both rigid, flexible, semi-flexible and energy absorbing, andmixtures thereof. Those skilled in the art will appreciate that withrespect to back-filling SRIM processes, cover stock materials are oftenreferred to as `vinyl` whether or not they are comprised of polymericethylene. As used herein, the term vinyl is intended to encompass boththe traditional chemical meaning, (i.e., polymeric ethylene) as well asthe meaning typically given to those familiar with SRIM molding process.

The cover stock materials may be formed prior to their insertion intothe composite article mold by vacuum forming. Alternatively, cover stockmaterial may be formed of PVC which is been rotationally cast. Asdiscussion of such processes may be found in the Polyurethane Handbook,G. Oretal, Section 5.4, pages 223-225 hereby incorporated by reference.

It will be appreciated that the presence of the various internalcomponent elements requires that the internal mold release agent notinterfere with adhesion of the SRIM article thereto.

The molded SRIM articles having internal mold release properties of theinvention will generally have densities of from 10 to 30 without glassand from 15 to 40 with glass. More preferably, the densities of the SRIMarticles of the invention all have densities from 20 to 35. They arefurther characterized by warpage of no more than approximately 0.25percent to 0.75 percent and a dimensional stability of no more than 0.10at 38° C. and 100% RH. Dimensional stability at 24 hours and 70° C. isno less than 0.01 percent. Tensile strength of the molded SRIM articlesranges from 2000 psi to 4000 psi. The flexule strength is from 3000 psito 7000 psi and the flexule modules is from 100 Kpsi to 200 Kpsi. Themolded articles show no cracking and an impact resistance of 0.9 J at23° C.

The following working examples indicate the manner and process of makingand using the invention and set forth the best mode contemplated by theinventors of carrying out the invention, but are not to be construed aslimiting.

The following ingredients were employed to illustrate the variouscompositions of the invention:

Polyol A is a propylene oxide adduct of vicinal toluenediamine having anOH number of 390.

Polyol B is a propylene oxide adduct of glycerin having an OH number of398.

Polyol C is a propylene oxide adduct of sucrose/diethylene glycol havingan OH number of 397.

Polyol D is a propylene oxide adduct of glycerin having an OH number of935.

Polyol E is a polyester polyol having an OH number of 65.

DABCO® 8800 is a delayed gel catalyst commercially available from AirProducts Corporation.

POLYCAT® SA-1 is a delayed blow catalyst commercially available from AirProducts.

Dow Corning® Fluid 5000 is a silicon-containing polymer commerciallyavailable from Dow Corning or Air Products Corporation.

FOMREZ®⁵ UL-32 is a dioctyltin dimercaptide catalyst commerciallyavailable from Witco Corporation.

LEXOREZ®⁶ 1721-65 is an adhesion promoter commercially available fromInolex Corporation.

TEGOSTAB® B 8863Z is a cell stabilizer commercially available fromGoldschmidt Chemical.

XFK-1546® is a silicone surfactant commercially available from AirProducts Corporation and believed to be equivalent to DC-5000.

PALATINOL®⁷ 11P-E is di-undecyl phthalate and is commercially availablefrom BASF Corporation.

EP-8 is an epoxidized tallate commercially available from Union Carbide.

DRAPEX®⁸ 6-8 is an epoxidized soybean oil commercially available fromWitco.

Isocyanate A is a polymeric-MDI having about 45-47 weight percent,2-ring MDI; 19 weight percent 3-ring MDI; and 30-33 weight percentn-ring MDI oligomers where n>3. The isocyanate has an NCO content of31.6 weight percent.

EXAMPLE 1

The following example illustrates the unexpected results achieved withthe internal mold release composition of the invention.

Three polyol components were prepared having the formulations indicatedbelow:

POLYOL COMPOSITIONS

    ______________________________________                                        FORMULATION    A          B      C                                            ______________________________________                                        POLYOL A P736  50.70      50.70  50.70                                        GLYCERIN       5.00       5.00   5.00                                         H.sub.2 O      3.00       3.00   3.00                                         SA-1           0.40       0.40   0.40                                         DABCO 8800     1.30       1.30   1.30                                         FOAMREZ UL-32  0.04       0.04   0.04                                         LEXORE Z 1721-65                                                                             2.00       2.00   2.00                                         DC-5000        3.20       3.20   3.20                                         EP-8           30.0       --     --                                           PALATINOL 11P-E                                                                              --         30.0   --                                           DRAPEX 6-8     --         --     30.0                                         TEGOSTAB B8863Z                                                                              3.0        3.00   3.00                                         ______________________________________                                    

Each of the above polyol compositions A, B, and C were combined withisocyanate A at an index of 110, i.e. 100 parts polyol to 110 partsisocyanate to form three different polyurethane compositions A, B, andC.

For each SRIM part, a fiberglass mat weighing between 200 to 300 gramswas used, with the average mat weighing approximately 222 grams. Thefiberglass used was 1 ounce NICO 754.

The parts were molded in an EMB PU SV, a high pressure dispensingmachine. The mold used was a door mold and had a metal surface andinternal heating coils. The temperature of the mold surface wasapproximately 150° F. The internal temperature of the shut mold was 150°F. For each part run, the mold, having an approximate part dimension of2×3 feet, was charged with the above polyurethane compositions, eachcomponent, i.e. the isocyanate (I) or the polyol side (II) having atemperature of 80° F.

The intention was to mold as many parts as possible until the quality ofrelease was deemed unacceptable; i.e. failed to lift out easily andrapidly.

The mold surface was initially prepared by stripping with solventfollowed by a soap (Ivory bar soap) and water wash. This was followed byan initial application of a light coat of LH-1, a hydrocarbon based wax,commercially available from Chemtrend of Howell, Mich. Five passes ofthe filling arm were necessary to fill the mold. It took approximately14 seconds to clamp the mold. Cure occurred 60 seconds after clamp.

    ______________________________________                                                     # OF RELEASES BEFORE                                             POLYURETHANE QUALITY OF RELEASE DEEMED                                        COMPOSITION  UNACCEPTABLE                                                     ______________________________________                                        A            18-20                                                            B            40-45                                                            C            6-8                                                              ______________________________________                                    

The results indicate that the polyurethane composition of the invention,i.e. composition B, performs advantageously as compared to prior artcompositions.

EXAMPLE 2

The effect of compounds (a) and (b) alone as compared to (a) and (b)together was measured. The following polyol compositions were prepared.

    ______________________________________                                        FORMULATION     1          2      3                                           ______________________________________                                        POLYOL A        58.30      58.30  58.30                                       PALINTOL 11P-E  25.00      --     25.00                                       GLYCERINE       10.00      10.00  10.00                                       DMCHA           0.80       0.80   0.80                                        BL-19           0.20       0.20   0.20                                        METHYL IMIDAZOLE                                                                              0.20       0.20   0.20                                        LEXOREZ 1721-65 2.00       2.00   2.00                                        DC-5000/DC 1245 2.25       2.25   --                                          WATER           1.25       1.25   1.25                                        ______________________________________                                    

The above polyol compositions, 1, 2, and 3 were combined with iso A atan index of 100 to form polyurethane compositions 1, 2, and 3. Plaqueswere handmade using a 12"×12"×0.25" aluminum mold initially prepared bystripping with solvent followed by a soap (Ivory bar soap) and waterwash. This was followed by two coats of LH-1, a hydrocarbon based wax,commercially available from Chem-Trend of Howell, Mich.

A fiberglass mat weighing between 200 to 300 grams was used, with theaverage mat weighing approximately 222 grams. The fiberglass used was 1ounce NICO 754.

The intent was to mold successive plaques until unacceptable stickingoccurred.

Fifteen successive plaques were molded using polyurethane compositionNo. 1. All 15 releases including the last one were excellent. Successivemolding was stopped using polyurethane composition No. 1 due to a lackof fiberglass mat.

Polyurethane composition No. 2 exhibited poor flow and stuck after thesecond molding. The resulting partially cured foam had to be strippedfrom the mold surface.

Three plaques were molded using the polyurethane composition No. 3. Thelast release was extremely poor and stuck to the mold surface.

Accordingly, neither the presence of silicone (a) alone, (compositionNo. 2), nor compound (b) alone, (composition No. 3), yielded acceptableresults. Rather, it is the unexpected synergy between (a) and (b) whichproduces an internal mold release agent, i.e. that used in compositionNo. 1, which yields advantageous results.

EXAMPLE 3

The effect of compound (b) alone as compared to (a) and (b) together wasagain measured using a different polyol. The following polyolcompositions were prepared.

    ______________________________________                                        FORMULATION        4      5                                                   ______________________________________                                        POLYOL B           35.39  32.00                                               POLYOL C           15.81  16.00                                               POLYOL D           10.00  15.00                                               GLYCERIN           5.00   5.00                                                DMCHA              0.8    0.8                                                 X-8154             1.30   1.30                                                H20                2.50   2.50                                                XFK-1546           4.0    --                                                  PALINTOL 11 P-E    25.00  25.00                                               ______________________________________                                    

The above polyol compositions 4 and 5 were combined with Iso A at anindex of 100 to form polyurethane compositions 4 and 5.

Handmix reactivity was as follows:

    ______________________________________                                        CREAM TIME          23 SECONDS                                                TOP OF CUP          46 SECONDS                                                GEL TIME            56 SECONDS                                                RISE TIME           62 SECONDS                                                ______________________________________                                    

Plaques were hand made using a 12"×12"×0.25" aluminum mold. The moldsurface was initially prepared by stripping with solvent followed by asoap (Ivory bar soap) and water wash. This was followed by an initialapplication of a light coat of LH-1, a hydrocarbon based wax,commercially available from Chemtrend of Howell, Mich.

Successive plaques were molded until sticking occurred and applicationof an external mold release agent became necessary.

10 plaque releases were obtained using polyurethane composition No. 4.Only 2 plaque releases were possible using polyurethane composition No.5. Plaques made with polyurethane composition No. 5 stuck very badly tothe mold surface.

Thus, as a result of the use of the compositions of the invention, theneed to spray additional IMR agents is substantially reduced.

The average performance properties of the resulting finished partsproduced according to Example 1 and using polyurethane compositionFormulation B were as follows:

    ______________________________________                                        PHYSICAL PROPERTIES     VALUE                                                 ______________________________________                                        Density (with glass)    33.7 pcf                                              Foam Density            26.0 pcf                                              Warpage                 .12                                                   Dimensional Stability   .05%                                                  38° C. and 100% RH                                                     Dimensional Stability   . 05%                                                 24 hrs. and 70° C.                                                     Tensile Strength        2730 psi                                              Flexural Strength       5180 psi                                              Flexural Modulus        162,700 psi                                           Impact Resistance 0.9 J and 23° C.                                                             No Cracking                                           Fiber Glass, Wt.        1 oz/ft.sup.2                                         ______________________________________                                    

I claim:
 1. A process of making a molded polyurethane article havinginternal mold release properties, the process comprising:providing amold; placing in the mold, a composition comprising:I.) an isocyanatecomponent; and II.) an isocyanate-reactive polyol component,comprising:A.) an isocyanate-reactive polyol comprising apolyoxyalkylene polyether polyol having an amine substituted aromaticmolecule as an initiator and having a molecular weight from 100 to about10,000; and B.) an effective amount of an internal mold releasecomposition, comprising:a.) a silicon-containing polymer; and, b.) an atleast diester functional compound which is the reaction product of:(i)an aromatic dicarboxylic acid; and (ii) alcohols having from 2 to 30carbons; and allowing the composition to react within the mold for atime sufficient to produce a molded polyurethane article having internalmold release properties.
 2. The process of claim 1 wherein the polyol(A) is an oxypropylated, toluene diamine-initiated polyol.
 3. Theprocess of claim 2 wherein the polyol (A) has a number average molecularweight of from about 400 to 700 and an OH number of from 300 to
 500. 4.The process of claim 1 wherein the composition placed in the mold has aninternal mold release composition (B) wherein the silicon-containingpolymer (a) is a secondary hydroxyl functional polydimethylsiloxane. 5.The process of claim 1 wherein the composition placed in the mold has aninternal mold release composition (B) wherein compound (b) comprises thereaction product of:(i) an aromatic dicarboxylic acid having from 8 to12 carbons; and (ii) one or more aliphatic monofunctional alcoholshaving from 4 to 15 carbons.
 6. The process of claim 5 wherein the atleast diester functional compound (b) comprises the reaction productof:(i) an aromatic dicarboxylic acid having from 8 to 12 carbons; and(ii) one or more aliphatic monofunctional alcohols having from 8 to 11carbons.
 7. The process of claim 6 wherein the at least diesterfunctional compound (b) comprises the reaction product of:(i) anaromatic dicarboxylic acid selected from the group consisting ofphthalic acid, terephthalic acid, and isophthalic acid; and (ii) analiphatic monofunctional alcohol having from 8 to 11 carbons.
 8. Theprocess of claim 7 wherein compound (b) is di-undecylphthalate.
 9. Theprocess of claim 1 further comprising placing a fiberglass mat withinthe mold.
 10. The process of claim 1 wherein the composition is allowedto react within the mold for less than one minute.
 11. A method ofmaking a composite molded article, comprising:placing within a compositearticle mold, a cover stock; subsequently placing within the compositearticle mold, a molded polyurethane SRIM article having internal moldrelease properties, the SRIM article being produced by the processcomprising: providing an SRIM article mold; placing in the SRIM articlemold, a polyurethane SRIM composition comprising:I.) an isocyanatecomponent; and II.) an isocyanate-reactive polyol component,comprising:A.) an isocyanate-reactive polyol comprising apolyoxyalkylene polyether polyol having an amine substituted aromaticmolecule as an initiator and having a molecular weight from 100 to about10,000; and B.) an effective amount of an internal mold releasecomposition, comprising:a.) a silicon-containing polymer; and, b.) an atleast diester functional compound which is the reaction product of:(i)an aromatic dicarboxylic acid; and (ii) alcohols having from 2 to 30carbons; and allowing the composition to react within the mold for atime sufficient to produce a molded polyurethane SRIM article havinginternal mold release properties; and removing the SRIM article from themold; providing within the composite article mold, a polyurethane foamcomposition; and allowing the polyurethane foam composition to reactinside the composite article mold for a time sufficient to produce acomposite molded article.
 12. The method of claim 11 wherein thepolyurethane foam composition is a flexible foam composition and ispositioned so as to join the cover stock to the SRIM article.
 13. Themethod of claim 12 wherein the flexible foam composition is between thecover stock and the SRIM article.
 14. The method of claim 12 whichproduces a composite molded article which exhibits no significantreduction in adhesion between the flexible foam and the cover stock. 15.The method of claim 11 wherein placing a cover stock within thecomposite article mold comprises placing a cover stock selected from thegroup consisting of vinyl, polyvinyl chloride, polypropylene,polyethylene, cloth, polyurethane foam, and mixtures thereof.
 16. Themethod of claim 11 wherein placing an SRIM article within the compositearticle mold comprises: placing within the composite article mold anSRIM article produced by the process further comprising providing withinthe SRIM article mold a fiber glass mat.
 17. The method of claim 11wherein the SRIM composition placed in the mold has an internal moldrelease composition (B) wherein the at least diester functional compound(B) comprises the reaction product of:(i) an aromatic dicarboxylic acidhaving from 8 to 12 carbons; and (ii) one or more aliphaticmonofunctional alcohols having from 4 to 15 carbons.
 18. The method ofclaim 17 wherein the SRIM composition placed in the mold has an internalmold release composition (B) wherein compound (b) comprises the reactionproduct of:(i) an aromatic dicarboxylic acid having from 8 to 12carbons; and (ii) one or more aliphatic monofunctional alcohols havingfrom 8 to 11 carbons.
 19. The method of claim 18 wherein the SRIMcomposition placed in the mold has an internal mold release composition(B) wherein the reaction product of:(i) compound (b) comprises anaromatic dicarboxylic acid selected from the group consisting ofphthalic acid, terephthalic acid, and isophthalic acid; and (ii) analiphatic monofunctional alcohol having from 8 to 11 carbons.
 20. Themethod of claim 19 wherein the SRIM composition placed in the mold hasan internal mold release composition (B) wherein compound (b) isdi-undecylphthalate.